The present invention relates to a drawer guide for a pull-out component of a piece of furniture, which includes a carcass rail fixedly attachable to an inner side of the piece of furniture and having a substantially C-shaped cross-section, a support rail for supporting the pull-out component, a substantially S-shaped middle rail arranged between the carcass and support rails and having at least two, arranged one above another, horizontal flanges which serve as tracks, a plurality of freely rotatable rollers provided on the two horizontal flanges, and a stop provided between the middle and support rails, with one of the plurality of rollers being arranged at a rear end of the support rail and with the stop cooperating with the one roller for limiting a pull-out path between the middle and support rails.
Drawer guides of the above-described type are known (see, e.g., Austrian Patent No. 372,829). Such a drawer guide proved to be a particularly useful for heavily loaded drawers. A particular problem, associated with such drawer guides, consists in shaping of stops which limit the pull-out path of the support rail with respect to the middle rail. The support rail, before it is mounted in the guide, need be secured to the drawer. As a result, for mounting of the drawer on the carcass and middle rails, which are already mounted in the furniture body, one more displacement plane is needed, namely, a vertical plane. Only in this vertical plane, the support rail can be pivoted for mounting the drawer on the already mounted guide parts. However the pivot angle, which is available in this type of guides, is rather limited. That means that a stop, which is provided on the support rail for limiting the pull-out displacement, should be provided not only near the upper horizontal flange of the support rail but should also have, in addition, only a small height. Furthermore, the stop should be made releasable and replaceable to enable its easy replacement in case the support rail, together with the drawer, could not be mounted. All this complicates the shaping and manufacturing of the stop, which makes it rather expensive. The requirement that the stop be mounted high on the support rail and, thus, have a relatively small height results in that the stop easily overruns the front track roller or the support roller of the middle rail, especially, when the drawer is heavily loaded, and the pull-out is effected with so-called "leap." In such drawer guides, the stop instead of abutting the front track or support roller provided on the middle rail and, thus, ending the pull-out displacement of the support rail, the stop leaps, because of its particular construction, over the roller provided on the middle rail, and the support rail moves, further, without being braked, until it falls on the floor, unless the displacement of the support rail is not stopped by some other means. The failure to stop the displacement of the support rail can result in a damage of a drawer and the drawer unit, and this can lead to an injury of anybody close to the furniture. To avoid this drawback, it was proposed to mount the stop on the lower flange of the middle rail of the above-described drawer guide with a possibility of a sidewise swinging out (Austrian Patent No. 372,829). To this end, the stop was mounted with a possibility to pivot about an axis extending vertically to the flange plane. However, to effect such a stop mounting, providing of a pivot axis became necessary which increases the mounting costs not insubstantially. Further, for the stop to be able to pivot or swing out sidewise, a vertical web of the stop carrying flange should be cut out adjacent to the stop. The size of the cut-out should be relatively large to provide for free and unhindered displacement of the stop. This results in weakening of a substantial portion of the load-carrying web of the rail.
To eliminate the above-discussed drawback, it was proposed to provide a locking bar in the end region of the middle rail. This locking bar reduced the gap between the bottom of the middle horizontal flange of the middle rail and the upper side of the upper horizontal flange of the support rail. In this way, the support rail was prevented from lifting off of the support roller of the middle rail when the stop, which limits the pull-out path of the support rail, run on the support roller, whereby the stop could not overrun the support roller. However, the projecting locking bar forms a separate part which should be fixedly attached to the middle rail after mounting of the support rail on the middle rail. Because of this, the support rail or the drawer can be dismounted and removed from the guide only after the removal of the locking bar. Besides this locking bar can easily be lost. Moreover, any additional part which need be manufactured and mounted increases the costs of the assembly.
An Austrian patent No. 393,781, which corresponds to U.S. Pat. No. 4,938,609, discloses providing, above the stop, of a slide in a slot of the horizontal flange of the support rail for preventing lifting off of the support rail of the support roller of the middle rail. This slide reduces the gap between the bottom of the middle horizontal flange of the middle rail and the upper side or surface of the supper horizontal flange of the support rail. At that, the edge portions project into the grooves, which are provided in the slide, whereby the slide is able to move along the flange in an axial direction of the rail. This slide adequately performs its designed function, however, the access to it is rather difficult, with a portion of a slide being almost completely unaccessible, in particular in roll-top desks, where the drawer guides are covered with side aprons.
Accordingly, an object of the invention is to provide in a drawer guide of the above-discussed type, in particular in a drawer guide similar to that disclosed in Austrian patent No. 372,829, a stop which would have a size sufficient to prevent the track roller of the support rail from overrunning the stop even when the support rail or the drawer, which is carried thereon, is sharply pulled out and which, at the same time, can be easily mounted.
Another object of the invention is to provide a relatively large stop for which weakening of the vertical web of the rail by a cut-out would not be needed.